Kiln for crucibles



2' Sheets Sheet 1.

(No Model.)

G. NIMMO. KILN FOR GRUOIBLES.

Patented Jan..6, 1891.

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(No Model.) 2 Sheets-Sheet 2.

G. NIMMO. KILN FOR GRUGIBLES.

N0. 444,153.- Patented Jan. 6 1891.

gag/(QM 7% m: uhnms warms 420., FNDTO- wu 1 c UNITED STATES PATENTOFFICE.

GEORGE NIMMO, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR TO THE GEORGE NIMMOCOMPANY, OF NEIV JERSEY.

KlLN FOR CRUCIBLES.

SPECIFICATION forming part of Letters Patent No. 144,153, dated January6, 1891.

Application filed December 17, 1889. Serial No. 334,024. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE NIMMo, a citizen of the United States,residing at Allegheny city, county of Allegheny, and State ofPennsylvania, have invented certain new and useful Improvements in KilnsforBakin g and Burning Orucibles, of which the following is such a full,clear, and exact description as will enable any one skilled in the artto which it appertains to make and use the same, reference being had tothe drawings forming part of this specification.

My invention relates to kilns for baking and burning crucibles, pots,and the like.

The old brick-constructed form of cruciblekiln has to be made of such alarge size as to require much space, is expensive to build, and is slowin its operation. In its use the crucibles are made in large quantities,dried in the air, then carefully introduced in the kiln, and stackedtherein with seggars to separate them. After the kiln is so charged orfilled it is closed up and fired, and the crucibles are baked and burnedwhile stationary in stacks. The kiln is then shut down or stopped inoperation, partially taken apart, and the lot of burnt cruciblesremoved. Thus it necessitates the labor and expense of accumulating asufficient lot or number of crucibles to fill the kiln before firing, aswell as necessitating much labor in stacking and unstacking thecrucibles in the kiln. Moreover, the heat and fire cannot be distributeds0 uniformly as to bake and burn each crucible alike. Consequently itproduces some articles which are not up to the standard. \Vith such akiln a weeks time is required to properly stack, bake, and burn andremove the crucibles, and it is practically impossible to bake and burna crucible of any desired size at short notice.

I overcome the aforesaid objections by my improved kiln, a type of whichis illustrated in the accompanying drawings, wherein Figure 1 is a topplan view of a kiln made after the manner of my invention. Fig. 2 is aside view of the same in section on planes indicated by line 2 2,Fig. 1. Figs. 3 and 4 are enlarged views of the respective ends of thekiln. Fig. 5 is an enlarged View in section on the line 5 5, Fig. 2.

Referring to the drawings, 7 designates a fire or fuel chamber providedwith a fire-door 9 and a grate 8, having an ash-pit 10 below the same.The foundation or substructure of the fuel-chamber may be constructed inany suitable manner, and in addition to the fire-door I provide thischamber with a suitable door 1] through which the burned ware maybeconveniently removed from the chamher by means of implements when thesame has been burned orfired to a proper degree.

From one side of the fuel-chamber, preferably the rear, extends theheating or baking chamber 12 in free communication therewith, in orderto allow the flame and heat to readily pass into the baking-chamber, andthe baked crucibles to be easily thrown by the conveyer into the fire.The baking-chamber is preferably disposed horizontally, and is madecomparatively long and narrow. It is provided at its end distant fromthe fuelchamber with a door or gate 13, through which the unbakedpottery or crucibles may be introduced therein and placed upon the conveyer.

The sides and top of both the fuel and baking chamber are constructed ofdetachable portable sections 1 1, consisting of plates or slabs ofmaterial adapted to the requirement of a kiln. The meeting edges ofthese plates are suitably tongued and grooved, as at 15, and the platesforming the sides of the chamber are detachably held together by meansof tie-rods 16 16, extending between the plates transversely of thechamber. The top plates 14 are laid upon and supported by the tie-rods16, though any other suitable way of sustaining them may be adopted. Thekiln is braced longitudinally by long binding-rods 17 17, which extendthe length thereof and hold the cross-bars 18 18 firmly against the endsof the kiln, respectively. This construction admits of the easy removaland transplanting of practically the entire kiln. The bottom of thebaking-chamber 12 may be constructed of masonry or suitableheat-resisting material, or, if preferred, may be made in sectionssimilar to the walls and top of the chamber, thereby also admitting ofeasy removal.

The smoke-pipe 19 for carrying off the products of combustion islocated, preferably, at

the extreme or distant end of the bakingchamber 12, so as to compel theflame, heat, and products of combustion issuing from the fuel-chamber topass through this chamber, thereby economizing the heat, simplifying theconstruction, and renderingthe kiln very efficient.

The heating-chamber 12 being comparatively of great length, the endthereof thatis distant from the fire-chamber will of course be oflowertemperature than any other point of its length, the temperature inthe chamber gradually increasing as the fuel-chamber is approached. Byvirtue of this arrangement a dried or prepared crucible introduced atthe distant or cool end of the baking-chamber 12 may be graduallysubjected to increasing temperature, and thereby gradually and uniformlybaked by moving it slowly along said chamber toward the fuel-chamber,passing it through the flames issuing therefrom, and then depositing itdirectly onto the burning fuel or coals. Thus by my invention thearticle to be baked and burned is carried gradually to the fire throughgradually-increasing temperature, and in carrying out this importantfeature of the invention I placea convcyer 20 within thebaking-chamber12 for slowly conveying the crucibles from the cool end of thebaking-chamber up to the burning fuel and delivering them directly ontothe same. The conveyer herewith shown consists in a series of endlessbelts or chains 21, suitably disposed and mounted on idlerpulleys 22,supported on shafts 23, which are set across the chamber 'with theirends restin g in the sides thereof. The conveycr-chains receive theirmotion from a suitably-driven shaft 2t through sprocket-wheels 25, andall of them move at the same rate of speed, their upper portionstraveling in the direction of the adjacent arrow a. This conveyerextendsa little short of the fuel-chamber 7, and between its end and thefire-chamber is arranged an incline or chute 26, over which thecruelbles pass from the conveyer to the burning fuel when they arethrown from the end of the conveyor by the motion thereof. Any suitableform of a conveyer may be used, and any suitable motor maybe employedfordriving the same.

Any of the crucibles may be readily inspected and reached by tools toadjust them and remove damaged or broken crucibles at any point of theirpassage through the baking-chamberby means of suit-ably constructed andarranged openings, such as27, formed in the sides of the chamber, andprovided with sliding covers 28, which are to be operated by hand touncover the opening to permit visual inspection, manipulation, orremoval of any of the crucibles near the particular opening.

In the operation of the kiln the conveycr is kept in slow motion in thedirection of the arrow (1, and the fuel in the chamber 7 is keptburning. The crucibles in an unbaked condition are placed upon theconveyer at the end thereofnear thedoor in thebaking-chamher, and areslowly carried by the conveyor toward the burning fuel. In their slowpassage they are thoroughly and uniformly dried and evenly baked, sothat by the time the other end of the couveyer is reached they are incondition to be passed through the flames, and then placed directlyontothe burning fuel and bu rned,an d thisis accomplished by means of theconveyer dropping the crucibles onto the chute, down which they passdirectly onto the burning fuel, from which they maybe removed bysuitableimplements after they have been burned a sufficient time.

In practice I am accustomed to allow the crucibles after being depositedon the burning fuel to remain thereon until they are baked or burned tothe degree of heat required. When the crucibles have been burned to sucha degree, I then remove them from the fire.

The important advantages of the invention are that the unbaked cruciblesmay be raised gradually from a low temperature to a very high one insuch a slow and gradual manner that they may be thoroughly dried anduniformly baked before reaching the fire itself, and that a great numberof crucibles can be baked and burned in a few hoursthree to four-fromthe placing of the first lot in the kiln, and also the great facilitywith which the crucibles may be inspected, manipulated, and removed atany point of their progress through the kiln. Another importantadvantage is that since the crucibles are burned one after another, andnot simultaneously in a lot, the first ones burned can be withdrawn andexamined to ascertain if the kiln is working properly. If any defect befound, the operation may be stopped, and thus the making of a lot ofdefective and worthless articles prevented.

Having thus described my improvements in kilns for baking and burningcrucibles and the like, what I claim as my invention, without limitingmyself to the construction shown,

1. A kiln for baking and burning crucibles, comprising a long narrowbaking-chamber having a chimney and a charging-door at one end, afuel-chamber in the opposite end of the baking-chamber communicatingfreely therewith, and a traveling conveyor within the baking-chamber forslowly moving the crucibles along the chamber from its charging end anddelivering them to and upon the burning fuel in the fuel-chamber,whereby the crucibles are baked in their passage through thebaking-chamber, and are then deposited directly onto the burning fueland burned, substantially as described.

2. A kiln for baking and burning crucibles, comprising a long narrowbaking-chamber having a chimney and a charging-door at one end, afuel-chamber in the opposite end of the baking-chamber communicatingfreely therewith, a traveling conveyor within the long baking-chamberand baking them while being conveyed slowly therethrough to the I5opposite end, and then depositing said crucibles directly onto the fuelin the fire-chamber and burning them, substantially as described.

In testimony whereof I have hereunto set my hand, this 22d day ofNovember, 1889, in the :0 presence of the two subscribing witnesses.

GEORGE NIMHO. Witnesses:

GEo. WHITEFORD, JOHN A. BLAIR.

